[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v7 04/17] vt-d: VT-d Posted-Interrupts feature detection
VT-d Posted-Interrupts is an enhancement to CPU side Posted-Interrupt. With VT-d Posted-Interrupts enabled, external interrupts from direct-assigned devices can be delivered to guests without VMM intervention when guest is running in non-root mode. CC: Yang Zhang <yang.z.zhang@xxxxxxxxx> CC: Kevin Tian <kevin.tian@xxxxxxxxx> Signed-off-by: Feng Wu <feng.wu@xxxxxxxxx> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> --- v7: - Remove pointless "if non iommu_intremap then disable iommu_intpost" logic - Don't need to check !iommu_intremap or !iommu_intpost when setting iommu_intpost to 0 v5: - Remove blank line v4: - Correct a logic error when setting iommu_intpost to 0 v3: - Remove the "if no intremap then no intpost" logic in intel_vtd_setup(), it is covered in the iommu_setup(). - Add "if no intremap then no intpost" logic in the end of init_vtd_hw() which is called by vtd_resume(). So the logic exists in the following three places: - parse_iommu_param() - iommu_setup() - init_vtd_hw() xen/drivers/passthrough/vtd/iommu.c | 14 ++++++++++++-- xen/drivers/passthrough/vtd/iommu.h | 1 + 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c index 1dffc40..8dee731 100644 --- a/xen/drivers/passthrough/vtd/iommu.c +++ b/xen/drivers/passthrough/vtd/iommu.c @@ -2147,8 +2147,8 @@ int __init intel_vtd_setup(void) } /* We enable the following features only if they are supported by all VT-d - * engines: Snoop Control, DMA passthrough, Queued Invalidation and - * Interrupt Remapping. + * engines: Snoop Control, DMA passthrough, Queued Invalidation, Interrupt + * Remapping, and Posted Interrupt */ for_each_drhd_unit ( drhd ) { @@ -2176,6 +2176,14 @@ int __init intel_vtd_setup(void) if ( iommu_intremap && !ecap_intr_remap(iommu->ecap) ) iommu_intremap = 0; + /* + * We cannot use posted interrupt if X86_FEATURE_CX16 is + * not supported, since we count on this feature to + * atomically update 16-byte IRTE in posted format. + */ + if ( !cap_intr_post(iommu->cap) || !cpu_has_cx16 ) + iommu_intpost = 0; + if ( !vtd_ept_page_compatible(iommu) ) iommu_hap_pt_share = 0; @@ -2201,6 +2209,7 @@ int __init intel_vtd_setup(void) P(iommu_passthrough, "Dom0 DMA Passthrough"); P(iommu_qinval, "Queued Invalidation"); P(iommu_intremap, "Interrupt Remapping"); + P(iommu_intpost, "Posted Interrupt"); P(iommu_hap_pt_share, "Shared EPT tables"); #undef P @@ -2220,6 +2229,7 @@ int __init intel_vtd_setup(void) iommu_passthrough = 0; iommu_qinval = 0; iommu_intremap = 0; + iommu_intpost = 0; return ret; } diff --git a/xen/drivers/passthrough/vtd/iommu.h b/xen/drivers/passthrough/vtd/iommu.h index ac71ed1..22abefe 100644 --- a/xen/drivers/passthrough/vtd/iommu.h +++ b/xen/drivers/passthrough/vtd/iommu.h @@ -61,6 +61,7 @@ /* * Decoding Capability Register */ +#define cap_intr_post(c) (((c) >> 59) & 1) #define cap_read_drain(c) (((c) >> 55) & 1) #define cap_write_drain(c) (((c) >> 54) & 1) #define cap_max_amask_val(c) (((c) >> 48) & 0x3f) -- 2.1.0 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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